Magnetic field intensities fall off rapidly with increasing distance from their source (motor, transformer, or even a single wire carrying a large AC current), requiring the data logger to be mounted very close to (ideally directly on) the field source, making interference from other sources less likely.Magnetic field intensities fall off rapidly with increasing distance from their source (motor, transformer, or even a single wire carrying a large AC current), requiring the data logger to be mounted very close to (ideally directly on) the field source, making interference from other sources less...